The present invention relates to a tool for driving a rotary element, of the type comprising two main members, namely:
an adapter for coupling to the rotary element, this adapter being equipped with a mechanism for locking the coupling wherein the locking mechanism is unlockable and normally locked; and PA1 a main drive member for rotating the adapter. PA1 between the adapter and the main drive member there is freedom allowing a relative displacement that has a component along the axis of the adapter, and PA1 the main drive member is designed to unlock the locking mechanism simply under the effect of the relative displacement of this main drive member with respect to the adapter towards the distal end thereof. PA1 the relative displacement is a translational movement along the axis of the adapter; PA1 the tool further comprises an urging member, especially a spring, which tends to move the main drive member away from the distal end of the adapter; PA1 the urging member tends to press the main drive member against a stop integral with the adapter; PA1 the member urges the mechanism towards its locked position; PA1 the locking mechanism comprises a catch, especially a ball, arranged in a duct of the adapter which opens onto the peripheral surface of this adapter; and a locking rod mounted to slide in a second duct essentially parallel to the axis of the adapter and in particular coaxial with this adapter, between a locked position, in which it keeps the catch projecting beyond the peripheral surface of the adapter, and an unlocked position, in which it allows the catch to retract into its duct; and the locking rod comprises a head which cooperates with the main drive member during the relative displacement; PA1 the tool comprises a joint in which the main drive member is articulated about a pin secured to one of the two main members and passing at least through a slot in the other main member which is elongate in a direction parallel to the axis of the latter; PA1 the head of the locking rod and the distal end of the main drive member comprise mating positioning parts designed to cooperate in at least one predetermined angular position of the main drive member with respect to the adapter, especially when this member and this adapter are aligned; PA1 the positioning parts are male and female shapes designed to clip together, or magnets; PA1 the tool comprises elastic straightening mechanism which tends to keep the axes of the main drive member and of the adapter parallel or concurrent; PA1 the elastic straightening mechanism includes the urging member; PA1 the head of the locking rod and the distal end of the main drive member comprise flats pressed onto one another when the main drive member is aligned with the adapter; PA1 the joint forms a ball-type universal joint, the clearance on the machining of the slot of the ball defining the said freedom for relative displacement; PA1 the joint forms a ball-type universal joint, the clearance on the machining of the slot of the ball being increased to define the freedom for relative displacement; PA1 the joint is a simple joint of an articulated handgrip; PA1 the joint is a simple joint of a Hooke's-type universal joint; PA1 the joint is a swivelling polygon, especially a spherically-rounded hexagon; PA1 the main drive member is a bar perpendicular to the axis of the adapter and mounted to slide, on the one hand, along its own axis and, on the other hand, along the axis of the adapter, in at least one slot of the adapter which is elongate in a direction parallel to the axis of the latter; PA1 the main drive member is a bar perpendicular to the axis of the adapter and mounted to slide along its own axis through two slots in the adapter, one of which slots is elongate in a direction parallel to the axis of the latter; PA1 the main drive member has a body which forms an extension bar, the length of which is greater than three times the diameter of its main section.
The invention applies particularly to articulated tools such as universal joints used for the rotational drive of a screwing/unscrewing socket mounted on the adapter.
An example of a tool of this kind is described in U.S. Pat. No. 5,433,548. However, it has a relatively complicated structure because of the need to provide an additional piece dedicated to unlocking.